Quote Originally Posted by chemi-cool View Post
Asuming no gages will show you the right vacuum, 29" Hg will do.

Personaly, my old Gould vacuum pump changes the sound when reaches the maximum vacuum,

Congratulations!
OK, that sounds good...

But how do you know that the vacuum you achieved is standing and there is no moisture boiling off in the system?

Digital micron gauge every time